﻿#include<stdio.h>
#define NUM 8
int a[NUM+1];
main()
{	   	      	 
int number,i,k,flag,not_finish=1,count=0;
i=1;
a[1]=1;
printf("The possible configuration of 8 queens are:\n");
while(not_finish)
{	   	      	 
    while(not_finish&&i<=NUM)
    {	   	      	 
    for(flag=1,k=1;flag&&k<i;k++)
        if(a[k]==a[i])  flag=0;
    for(k=1;flag&&k<i;k++)
        if((a[i]==a[k]-(k-i))||(a[i]==a[k]+(k-i)))
            flag=0;
    if(!flag)
    {	   	      	 
        if(a[i]==a[i-1])
        {	   	      	 
            i--;
            if(i>1&&a[i]==NUM)
                a[i]=1;
            else if(i==1&&a[i]==NUM)
                not_finish=0;
            else a[i]++;
       }
      else
        if(a[i]==NUM)a[i]=1;
        else         a[i]++;
    }
    else if(++i<=NUM)
    {    if(a[i-1]==NUM)
            a[i]=1;
        else
            a[i]=a[i-1]+1;
    }
    }
    if(not_finish)
    {	   	      	 
        ++count;
        printf((count-1)%3?"  [%2d]:" : "\n   [%2d]:",count);
        for(k=1;k<=NUM;k++)
            printf(" %d",a[k]);
        if(a[NUM-1]<NUM)
            a[NUM-1]++;
        else a[NUM-1]=1;
        i=NUM-1;
    }
}	   	      	 
}	   	      	 
